请教Bell_lapadula model 和Biba model 的*(star)prooerty 的区别?

zhangcisco

Q1 what does the Bell-lapadula model NOT allow?\r\n\r\n1. Subgects to read from a higher level of security relative to their level of security\r\n2. Subjects to read from a lower level of security relative to their level of security\r\n3. Subjects to write to a higher level of security relative to their  level of security \r\n4. Subjects to read at their same level of security\r\n\r\n\r\nwhich answer? why? give me reason.\r\n\r\n\r\nQ2 The * (star)property of the Biba model states:\r\n\r\n1. Subjects cannot write to a lower level of integrity relative to their level of intergrity.\r\n2. Subjects cannot write to a higher level of integrity relative to their level of intergrity.\r\n3.Subjects cannot read to a lower level of integrity relative to their level of intergrity.\r\n\r\n4.Subjects cannot readto a higher level of integrity relative to their level of intergrity.\r\n\r\nwhich answer? why? give me reason.\r\n\r\n\r\n\r\nanswer Q1:1;Q2:2

linkenpark

bell:no write down不能往下写\r\n      no read up     不能往上读\r\nbiba:no write up\r\n      no read down

zhangcisco

谢谢\r\n\r\nbell为什么同级（高）不能写？有定义？\r\n\r\nbiba为什么同级（低）不能读？\r\n\r\n好像在bell?和bible 并没有这样定义！？？？\r\n\r\nQUOTE]最初由 linkenpark 发布\r\n[B]bell:no write down不能往下写\r\n      no read up     不能往上读\r\nbiba:no write up\r\n      no read down [/B][/QUOTE]

zhangcisco

我明白了，我理解错了。多谢回复！ \r\n\r\nQ1 HIGH --> LOW(WRITE)\r\n\r\nQ2 LOW--HIGH (READ)